In Mexico, Andres Manuel Lopez Obrador, candidate of the leftist Party of the Democratic Revolution, is charging election officials with "manipulation" of the vote count in Sunday's presidential election that shows ruling party candidate Felipe Calderon with a lead of about one percent. Lopez Obrador says he will file legal challenges if the final official count favors Calderon.

After more than 98 percent of the vote from Sunday's election had been counted, Felipe Calderon maintained a slight lead, which he said was supported by several independent exit polls that showed him as the victor. The Mexican Federal Electoral Institute, however, refrained from declaring any winner, having already announced a recount of the vote to commence on Wednesday.

Coming before reporters after the release of the initial vote count results, Lopez Obrador promised a legal challenge.

He says there was an evident manipulation of the preliminary vote count that would have to be explained. He points to inconsistencies in the count that appeared in the early morning hours as the preliminary results were released. He says he will challenge the result polling place by polling place, if necessary.

Many political analysts here and abroad have expressed concern that the fiery populist might call for massive protests in the streets if he was to lose this election, but Lopez Obrador asked his followers to remain calm, and said he would pursue legal challenges to the vote result. He did not, however, rule out calling for protests later if his legal challenges fail.

The statements by Lopez Obrador put him in conflict with the electoral institute that has run elections here in Mexico for the past several years, to the applause of international observers as well as Mexican citizens. Mexicans tend to hold the I.F.E., as the institute is known, in higher regard than they do most politicians.

Members of the leftist coalition that supported Lopez Obrador recall the 1988 election that leftist candidate Cuahtemoc Cardenas was widely believed to have won. The election machinery at that time was under the control of the Institutional Revolutionary Party, or P.R.I., and the final vote count gave the victory to P.R.I. candidate Carlos Salinas de Gortari.

The P.R.I. hold on power was broken with the election of Vicente Fox in 2000, the first election in which the independent and professional I.F.E. was in charge of all voting stations and vote counting. The P.R.I. candidate in this year's election, Roberto Madrazo, ran a distant third in the vote count.

Mexican financial markets responded to the prospect of a Calderon victory with a more than 4.7 percent jump in the stock market Monday and a strengthening of the Mexican peso. Analysts say many investors sold stock in the week or two leading up to the election when polls showed a possible win by Lopez Obrador. Investors were worried about the populist rhetoric of Lopez Obrador and his tendency to blame Mexico's wealthier classes for the nation's widespread poverty.

Calderon, on the other hand, is pro-business, and says the solution to poverty is job creation through economic expansion. He ran on a detailed platform that included judicial reform, fiscal reform and energy sector reform. President Fox has proposed some of the same reforms, but he was unable to get his proposals through a divided Congress.

Calderon, if his victory is confirmed, will face a similar divide, with no one party enjoying a majority. Calderon has said he will try to build coalitions and make deals with the other parties, something Mr. Fox was also unable to do.